Safety device for a carburettor control means

ABSTRACT

Safety device for throttling-down the speed of an engine on locking or deterioration of the carburettor control in the acceleration period. The said device comprises a detector for the pressure at the accelerator pedal, comprising a mobile means having two positions corresponding respectively to normal functioning of the acceleration control means and locking thereof, the said means being constantly pressed in resilient fashion against a location on the pedal, and an engine throttling-down device actuated by the detector in its locking position. This device may be applied to remote-control devices.

United States Patent [1 1 Remand 1 Oct, 1, 1974 [54] SAFETY DEVICE FOR A CARBURETTOR 3,731,667 5/1973 MacMillan 123/198 DB CONTROL MEANS Inventor: JacquesRemaud, Billancourt,

France Assignees: Regie Nationale des Usines Renault,

Billancourt; Automobiles Peugeot, Paris, both of, France Filed: Dec. 13, 1971 Appl. No.: 207,156

Foreign Application Priority Data Dec. 15, 1970 France 70.45100 U.S. Cl. 123/198 DB Int. Cl F02b 77/00 Field of Search.... 123/98, 108, 198 DB, 198 D References Cited UNITED STATES PATENTS MacMillan 123/198 DB Primary ExaminerCharles J. Myhre Assistant Examiner-R. H. Lazarus Attorney, Agent, or FirmStevens, Davis, Miller &

Mosher 5 7] ABSTRACT Safety device for throttling-down the speed of an engine on locking or deterioration of the carburettor control in the acceleration period.

The said device comprises a detector for the pressure at the accelerator pedal, comprising a mobile means having two positions corresponding respectively to normal functioning of the acceleration control means and locking thereof, the said means being constantly pressed in resilient fashion against a location on the pedal, and an engine throttling-down device actuated by the detector in its locking position.

This device may be applied to remote-control devices.

3 Claims, 8 Drawing Figures PATENEED 1 H874 sum 1 or d m '3 or 4 PATENIED UB1 1 974 PAIENIEnnm nan 3.838.674

'snmuurq SAFETY DEVICE FOR A CARBURETTOR CONTROL MEANS The present invention is intended to counter the difficulties arising in the event of locking of the carburettor control means in the engine acceleration position;

y when this occurs, in the event of seizing ofthe cable in its sheath, deterioration of the restoring spring or any similar incident, the engine is automatically caused to slow down or even to stop completely.

The device according to the invention comprises. essentially, a detection means which is responsive to the pressure on the accelerator pedal and a means for acting on the carburettor, thereby throwing down the engine as soon as presure on the accelerator ceases. The said device which is connected in series or in parallel relative to the normal accelerator-carburettor circuit may be actuated by electrical or electromagnetic, hydraulic or pneumatic means.

The accompanying drawings show, diagrammatically, and by way of non-[imitative example, five embodiments of the subject of the present invention.

FIG. 1 shows a first electromagnetic embodiment of the invention acting on the air flow in the carburettor.

FIG. 2 is an enlarged detail of the system responsive to the pressure exerted on the accelerator.

FIG. 3 is an electromagnetic variant acting on the fuel flow.

FIG. 4 is a hydrostatic safety control system.

FIGS. 5 and 6 illustrate a pneumatic variant acting on the control for the accelerator throttle valve.

FIGS. 7 and 8 refer to an electromagnetic embodiment of the device according to the invention.

The safety device shown in FIG. 1 is connected in parallel relative to the normal carburettor control circuit, comprising the pedal 1 which is mobile in rotation about a horizontal pivot 2. 1

As will more clearly be seen in FIG. 2, the pedal 1 carries on its rear face a mobile plate 4 which is also mobile about the pivot Land is connected at its lower portion to the control cable 5 for the carburettor throttle valve 6 which is subjected to the action of a recall spring 7.

A pressure-detecting device 8 is secured to the plate 4, separated from the pedal 1 by a leaf-spring 3, the action of which tends to maintain the pedal 1 and the plate 4 separate. The detector 8 comprises a contactor 9, the head of which bears on the lower face of the pedal and the further widened end 10 of which bears on a spring tending to press it on contacts connecting the conductors Hand 12. Referring to FIG. 1, the action of the spring exerted on the plate 10 is opposed by the pressure exerted on the pedal maintaining the previously described electrical circuit open.

Referring to FIG. 1, it will be seen that the conductor 11 terminates at the coil of an electromagnet 13 which is connected to a source of voltage connected for example with a circuitbreaker of contact-key or starter type. The core of the electromagnet is connected by a link to a second air butterfly-valve 14 disposed at the carburettor air inlet.

The butterfly valve 14 is able to adopt two positions,

electromagnet at rest the butterfly valve is opened,

electro-magnet excited the butterfly partly or completely closes the air inlet.

. In operation, when the driver exerts pressure on the pedal 1, he depresses the contactor 9 against the action of the spring 3 and then drives the plate 4 in rotation about pivot 2. The electric circuit is at open. Furthermore, the cable 5 which is pulled towards the right due to rotation of thepedal 1 drives the main butterfly valve of the carburettor in rotation in the sense of an acceleration increase.

During the inverse operation, if, due to an incident, the cable 5 does not return towards the left hand side in order to slow down the engine, the absence of pressure on the pedal 1 enables the spring 3 to move the plate 4 away from the pedal 1. When this happens. the contactor 9 establishes contact between an end of the conductor 11 and the mass at'l2, the further end. in which is connected in series the electromagnet 13 connected to the plus pole of the generator, is consequently excited and therefore displaces the butterfly valve 14 located upstream of the butterfly valve 6 into a position affording a small air passage corresponding to the slow running speed of the'motor.

It will be noted that the safety butterfly valve 14 could also be disposed upstream of the main butterfly valve 6 or could be incorporated in the carburettor, depending upon the design of the latter.

In the position corresponding to the slow speed of the engine, without action on the pedal 1 the contactor closes the electric circuit, so that the electromagnet 13 is excited and the butterfly valve 14 is partially closed. Thus, the engine runs at throttled-down speed.

FIG. 3 illustrates a variant of the device described hereinabove; in this case, the factor acted-upon in order to throttle-down the engine is a modification in the internal circuit of the carburettor, i.e., on the main jet in the present case, combined, where appropriate with any action the object of which it is to maintain optimum dosing in the mixture. The entire part of the device, the purpose of which it is to detect the pressure at the level of the pedal is identical with that described with reference to FIGS. 1 and 2.

The mode of acting on the carburettor or receiver involves, in this case, a needle 20, fast with the core 21 of an electromagnet 22 the winding 23 of which is connected to the conductor 11 extending from the pressure detector 8.

The needle 20 is disposed opposite the orifice of the main jet 24 and carries a pin 25 on which bears a spring 26 maintaining the needle in the position shown in FIG. 3; the jet orifice is free and the engine runs without stress.

In normal functioning, the electrical circuit comprising the conductor 11, the pressure detector 8 and the receiver 28 is open. The generator, the plus pole of which is connected to the electromagnet coil at 29 does not excite it and this is what is shown in the figure. On the other hand, in the event of locking of the accelerator in the position corresponding to engine racing," release of the foot from the pedal 1 permits operation of the spring 3. This permits the closing of the electrical circuit previously described by the plate 10 of the contactor 9; the electromagnet 22 is activated and urges the needle 20 into the orifice in the main jet 24, against the action of the spring 26. The fuel is then able to flow only through the throttle-down jet 27.

FIG. 4 relates to a hydrostatic application of the invention, having, as modified parameter, the air flow in the carburettor by means of the main butterfly valve 30. Opening of the air inlet is controlled by the pedal to which is articulated a link 33 bearing in a seating 34 formed in a deformable member 35 (made, for example, of natural or synthetic rubber); the latter, which is provided with a channel 36 extending through it, is lodged in the internal cavity of a piston 37 which is axially perforated at 38 and is provided with a packing 39 providing for fluid-tightness with the oil filled cylinder. The right-hand portion of the cylinder is closed by a fluid-tight deformable diaphragm 41 connected to an oil reservoir 42. On the opposite side, the cylinder comprises a vertical wall formed with an aperture debouching into a conduit 43 and on which bears a spring 44 tending to urge the piston 37 towards the right-hand side in the figure.

The free end of the conduit 43 is connected to one end of a cylindrical container 45 which is full of oil and the opposite face of which is sealed by a rotating diaphragm 46 enveloping a piston 47 articulated at 42 to the control means 49 for the carburettor butterfly valve. A spiral spring 50 tends to restore the butterfly valve into the position corresponding to throttlingdown of the engine.

In normal functioning, pressure exerted on the pedal 31 first of all presses the deformable element 35 against the orifice 38 of a piston 37 thereby isolating the chambers A and B. If action on the pedal continues the piston 37 is displaced against the action of the spring 44 and the fluid contained in the chamber A is delivered into thechamber C of the receiver 45, thereby urging the piston 47 which acts on the position of the butterfly valve 30 and on the engine speed.

If deceleration is triggered, the spring 50 urges the piston 47, thereby displacing the fluid from the chamher (I towards the chamber A.

This pressure,-acting on the piston 37, assisted by action of the spring 44, urges the assembly comprising the piston 37 and the resilient element 35 against the rod 33 whilst maintaining the duct 38 closed. During this time, the butterfly valve 30 returns to its position corresponding to throttle-down of the engine. The duct 38 is not re-opened until the end of travel, thereby permitting re-feeding of the circuit.

In the event of locking of the piston 37 in the cylinder 40,. thus preventing the withdrawal thereof, after release of the pedal 31, the resilient element (possibly assisted by a recall spring) is separated from the righthand wall of the piston 37 thereby freeing the duct 38.

The pressure oil contained in the cylinder returns into the reservoir 42 and then nothing opposes the return of the butterfly valve 30 to the position associated with slow running of the engine.

In the case of rupture of the conduit 43, the decrease in the pressure of the fluid contained in the cylinder 45 automatically reduces slowing-down of the engine due to partial or total closure of the air inlet after rotation of the butterfly valve 30 controlled by the spring 50.

FIGS. 5 and 6 refer to a pneumatic variant of a safety device according to the invention. 7

The pedal 51 and the plate 52 are both mobile about a horizontal pivot 53. A cable is connected at one of its ends to the base of the plate 52 and at its other-end to a link 55 which is mobile in rotation about a pivot 56 connected by a rod 57 to the receiver 58. The latter is comprised of a housing 59 separated into two fluidtight compartments by a flexible diaphragm 60 and controlling, through intermediary of a rod 61 and a link 62, the opening of the butterfly valve 63. The latter, which is free from stressing of any kind, is displaced into the position associated with throttling-down of the engine under the action of the recall spring 64.

The device 65, which responds to pressure of the foot on the accelerator. consists of a casing 66 connected on the one hand to a conduit the other end of which communicates with the lower compartment of the receiver and on the other hand with a connection to the external air 68. It comprises furthermore a pusher member 69 contacting the pedal 51 at one of its ends and bearing at its other end on the head formed with an orifice 72, of a blocking means 70, which normally closes the inlet of the conduit 67, against the action of a spring 71.

A branch 73, of the conduit 67, is connected to a negative pressure source and has a non-return valve 74 opposing penetration of air into the conduit 67V Under normal functioning conditions, pressure on the pedal 51 first of all blocks the conduit 67 due to the depression of the pusher 69. The negative pressure supplied by the conduit 73 is set up in the conduit 67 and in the receiver 58, thereby pressing the diaphragm 60 against the bottom of the casing and thus connecting the levers 62 and 55. If action on the pedal continues the traction effect of the accelerator cable, due to pivoting of the plate 52 about the pivot 53, results in rotation in the direction indicated by the arrow F of the links 55 and 62, which are connected by the receiver 58. In this way, the position of the butterfly valve 63 is modified against the action of the spiral spring 64.

On releasing the pressure on the pedal, negative pressure being still maintained in the receiver and the conduits, the pedal and the butterfly valve return into their first position under the action of the recall spring 64.

In a case of locking of the cable 54 in the sheath, the locking means subjected to the action of the spring 71, frees the aperture in the conduit 67, thus establishing connection between it and the external air via the conduit 68. When this has been done, the diaphragm subjected to the action of the spring 64 is able to move away until it bears on the upper portion of the actuator. During this displacement, the butterfly valve adopts the position corresponding to throttling-down or slowingdown of the engine.

FIG. 7 shows an embodiment involving electromagnetic control applied to the device according to the invention.

The receiver 75 constituted by a casing 76 through which extends a pivot 77 on which is fast on the one hand a stop 78 and, at the opposite end thereof, keyed deflecting means 79 controlling the carburettor butterfly valve.

Bearing against the stop 78 is a pulley 80 formed with front notches engaging with their homologues in the associated face of the stop78. The pulley 80 is mounted idly upon the pivot 77 and is formed in its periphery with a groove into which debouches and is secured the end of the cable 5 connected to the accelerator pedal. The pulley 80 is pressed against the stop 78 by a spring 82 acting on a circular armature 81; The opposite face of the spring bears on the bottom of a seating formed axially in the frame 83 of an electromagnet comprising a coil 84; the latter is put under voltage via the conductors 11 and 11, connected respectively to the pressure detector of the pedal in accordance with what was described with reference to FIGS. 1 and 2 and to the plus pole of a generator connected in series with a key circuit-breaker of Neiman type. Under normal running conditions, no current reaches the electromagnet and the receiver is in the position described with reference to FIG. 7.

Thus pressure on the cable 1 results in a traction effect on the cable 5 and the rotation of the pulley 80 pressed by the spring 82 on the lateral stop 78. The pivot 77 is put in rotation through an angle proportional to the displacement of the pedal and transmits the movement to the means for controlling the carburettor butterfly valve, against the action of a recall spring.

In the event of locking of the cable, as described with reference to FIG. 1, the electric circuit is closed at the level of the pedal contactor 9, the electromagnet attracts the armature 81 against the action of the recall spring 82 and thereby frees the pulley 80 from the stop 78. The pulley 80 rotates freely on the pivot 77 which no longer opposes the action of the recall spring returning the carburettor butterfly valve into the position corresponding to slowing-down of the engine.

Of course, the scope of the invention would not be exceeded if various modifications as to detail were to be effected, such as, for example, the selection, with reference to each embodiment described, of a different parameter for causing the engine speed to slow down in the event of locking of the acceleration controls or by adding of a supplementary resilient recall means in each of the variants, or by applying a device of this kin to a remote control system other than those providing for accelerator control in a vehicle.

What we claim is:

l. A safety carburettor control system for internal combustion engine adapted to return the engine speed to idle on locking or deterioration taking place in the carburettor control system during an acceleration period, comprising a carburettor, including a throttle lever, a plate and an accelerator pedal pivotably mounted about a same axis, means connecting said plate to said throttle lever and recall spring means to normally return the throttle lever to an idle position. second spring means of lesser force than said recall spring means being interposed between said plate and pedal, a vacuum operated servomeans being provided to return the engine speed to idle, and one control member for said servomeans being provided between said plate and pedal to place said servomeans in a state corresponding to the idle position when the pedal and plate are spaced of each other by said second spring means, said control member being constituted-by one valve which places said servomeans in communication with the atmosphere when said pedal and plate are spaced of each other.

2. A safety carburettor conjrol system according to claim 1, wherein said servomeans are inserted in said means connecting said plate to said throttle lever.

3. A safety carburettor control system according to claim 2, wherein said connecting means are of the cable type. 

1. A safety carburettor control system for internal combustion engine adapted to return the engine speed to idle on locking or deterioration taking place in the carburettor control system during an acceleration period, comprising a carburettor, including a throttle lever, a plate and an accelerator pedal pivotably mounted about a same axis, means connecting said plate to said throttle lever and recall spring means to normally return the throttle lever to an idle position, second spring means of lesser force than said recall spring means being interposed between said plate and pedal, a vacuum operated servomeans being provided to return the engine speed to idle, and one control member for said servomeans being provided between said plate and pedal to place said servomeans in a state corresponding to the idle position when the pedal and plate are spaced of each other by said second spring means, said control member being constituted by one valve which places said servomeans in communication with the atmosphere when said pedal and plate are spaced of each other.
 2. A safety carburettor conjrol system according to claim 1, wherein said servomeans are inserted in said means connecting said plate to said throttle lever.
 3. A safety carburettor control system according to claim 2, wherein said connecting means are of the cable type. 